Bake-oven.



UNITED STATES PATENT OFFICE.

CHARLES P. DOWD AND JOHN H. COLEMAN,- or SAN FRANCISCO, CALIFORNIA.

BAKE-OVEN.

SPECIFICATION forming part of Letters Patent No. '7 19,651, datedFebruary 3, 1903.

Application filed May 15, 1902.

To all whom it may concern:

. y y, Fig. 2.

Be it known that we, CHARLES P. DOWD and JOHN H. COLEMAN, citizens ofthe United States, residing in the city and county of San Francisco,State of California, have invented an Improvement in Bake-Ovens; and wehereby declare the following to be a full, clear, and exact descriptionof the same.

Our invention relates to improvements in bakers ovens of the typecommonly known as cracker-ovens, in which the heated products ofcombustion are discharged directly into the oven-chamber and in whichchamber is a revoluble reel or wheel with pendent trays carrying thearticles to be baked.

The object of our invention is to adapt these ovens to the use of oilfuel and to secure better means of heat distribution and control thanhas heretofore been possible.

It has been customary to build these ovens, which may be from fifteen totwenty feet in diameter, with two or more fire-boxes, using coke or hardcoal as a fuel. The difficulty has been to distribute the heat to bestadvantage in the oven-chamber. With a coke or coal fire oftentimesbutasmall proportion of the heat given off by one of the grates will beutilized in baking. We have found that by a certain arrangement of fluesand dampers and by using crude oil as fuel we can at all times regulatethe fuel feed to the amount of heat necessary in the oven-chamber andcan distribute the heat therein according to the nature of the articlesto be baked.

The invention consists of the parts and the constructions andcombinations of parts which we will hereinafter describe and claim.

Figure 1 is a horizontal section on the line Fig. 2 is a longitudinalsection on the line 0a 00, Fig. 1.

A represents an oven of any suitable size, shape, or material.

2 is a longitudinal fire-box extending centrally through the bottom ofthe oven-chamber 3.

Any suitable hydrocarbon-burner 4 is disposed in the front of thefire-box, and suitable draft-regulators 5 may be provided in the frontto admit air to effect perfect combustion.

The combustion-chamber 2 extends approxi- Serial No. 107,401. (Noniodel.)

mately two-thirds of the length of the chamber 3 and opens at the backinto the lateral lines 7, disposed one on either side of the wall of thefire-box, which flues extend nearly to the front of the oven-chamber, inwhich latter they are adapted to discharge. Parallel with the flues 7and separated therefrom by the partition-Walls 8 are the return-fines 9,which have their front ends opening into the oven-chamber coincidentlywith the fines 7 and their rear ends slightly inclined upwardly andopening into the said chamber. Dampers 10 are adapted to close up thefront ends of the flues 7 and 9 when it is desired to divert all theheat to the back of the oven,whereupon the rear dampers 11 will beopened. Each of the latter is operated by meansof the rod 12, extendingthrough the oven-chamber and the front wall of the oven and havingnotches 18 engaging a plate 14, whereby the damperopening may bevariedas desired. The dampers 10 may be similarly operated from the outside,or where furnaces already exist with doors, as 15, the latter may beopened to allow the operator to reach the rod 16, pivoted to eachdamper, and set it in one or the other of the notches 17 in a platesecured in the bottom of the oven-chamber.

The flues 7 and 9 extend to within a short distance of the walls of theoven-chamber, as shown, and the dampers 10 and 11 are at the ends ofsaid dues, for the reason that with an oil-burner where there is anintense draft continually in the combustion-chamber the heat may bedeflected against the walls of the oven-chamber to distribute it equallyin the latter. When the heat-blast issuing from either of these dampersstrikes the walls of the chamber, it is deflected equally upon all sidesand circulates through the chamber and finally issues from the front ofthe oven-chamber just above the openings where the goods are insertedandremoved.

In the rear of the fire-box there may be disposed a baffle-wall orpigeonhole structure 18 to assist in the retardation of the fuelproducts to effect completecombustion before entering the dues and theoven-chamber.

Issuing from either of the openings controlled by the dampers 10 and 11,the heat passes upwardly into the oven-chamber, in

which the intermittently-revoluble reel or carrier 19 is contained.

20 is a damper to regulate the direct draft from the fire-box to thechimney 19, which, as shown, is situated at one corner of the oven.

Heretofore these ovens have not been suited for baking certain classesof articles owing to the fact that the heat was deliverable only at oneend of the oven-chamber and that its distribution could not be asreadily controlled as desirable-that is, it has been customary to useflue-passages analogous to our lateral flues 7, whereby the heat wasdeliverable only into the front of the oven, which rendered the ovenunsuited for baking sweet stuffs,

which require browning on the top. By

adding the return-flues 9 and interposing the dampers 10 and 11 at frontor back of the oven the heat can be so equally distributed in theoven-chamber and to any part thereof that it is possible to readilyadapt the oven to any particular requirement.

The use of oil fuel allows the oven temperature to be raised or loweredalmost instantaneously-a matter of the utmostimportance.

With our furnace arrangement the use of oil is preferable to coal orcoke, as there is an entire absence of soot or unconsumed gases in theoven-chamber.

When the burner is first started, both sets of dampers 10 and ll areclosed and the draft is directly through the flue 18 in the rear Wall ofthe furnace into the chimney 19. The flue 18 is connected with thechimney bya flue 19*, which may be built along the bottom of the backend of the oven. As soon as a proper draft is induced the damper 20 inthe flue is closed and one or the other of the dampers 10 and 11 opened,whereupon the heat products pass through the flues 7 or 7 and 9 into theoven-chamber, and thence into the passage 21, connecting with thechimney.

The flues 9 are inclined upwardly for a portion of their length, asshown at 22, so that the point of discharge at the rear end of the fluesis above the discharge-point of the flues 7, as better draft is inducedthrough the re turn-flues when the dampers 10 are wholly closed, whileit allows the latter to be left partly Open and still cause a certainamount of heat to be delivered into the rear of the oven-chamber. Thisis often advantageous,

as it permits both front and rear of the oven to be heated equally.

Having thus described our invention, what we claim, and desire to secureby Letters Patent, is

1. The combination in an oven, of a single fire-box disposed centrallyin the bottom of the oven-chamber and terminating short of the rear endof said oven; partition-walls extending from the rear of the oven andterminating short of the front end and forming lateral and return flues,the fire-box opening at the rear into the lateral flues and thereturn-flues opening into the rear of the ovenchamber and having theirfront ends also opening into the oven-chamber coincidently with thelateral flues; and dampers controlling the ends of the flues and servingto direct the heat against the walls of the ovenchamber. r

2. An oven comprising a single fire-box disposed centrally in the bottomof the ovenchamber and terminating short of the rear end thereof;partition-walls on each side of the fire-box, extending from the rear ofthe oven parallel with and separated from the Walls of the fire-box andterminating short of the front end of the chamber, and forming lateraland return flues, said fire-box opening at the rear into the lateralflues and said return-flues opening into the rear of the ovenchamber andhaving their front ends also opening into the front of the oven-chambercoincidently with the lateral flues, and said return-flues having theirrear ends in a higher plane than the front ends; and dampers controllingthe ends of said flue-openings and directing the heat into either end ofthe ovenchamber and against the walls thereof.

3. The combination in an oven of a fire-box disposed centrally in thebottom of the oven- 5 chamber and terminating short of the rear of theoven, lateral flues into which the rear end of the fire-box opens, saidlateral flues terminating short of the front wall of the oven andadapted to discharge its heat against said front wall to diffuse theheat within the ovenchamber, return-flues having their front endsopening into the oven-chamber coincidently with said lateral flues, andhaving their rear ends terminating short of the rear wall of theoven-chamber, said return-flues choked at their rear ends and openinginto the ovenchamber to discharge their products against said rear wallto difiuse the heat within the oven-chamber, and dampers controlling theno open ends of said flues.

In witness whereof we have hereunto set our hands.

CHARLES P. DOWD. JOHN H. COLEMAN. Witnesses:

S. H. NOURSE, JESSIE C. BRODIE.

